org.sc3d.apt.sss.v3
Class NDFA.Transition

java.lang.Object
  org.sc3d.apt.sss.v3.NDFA.Transition

Enclosing class:

NDFA

public static class NDFA.Transition
extends java.lang.Object

Represents a transition of an NDFA. Instances are immutable, except for the 'ndfa' field which should be filled in by the caller when it is first needed.

Field Summary

Grammar	g A Grammar describing the Tree that is constructed by following this Transition, or 'null'.
NDFA	ndfa An NDFA describing the grammar of the contents of the bracket, if this is a 'bracket shift' Transition and its NDFA has already been calculated, or 'null' if this is not a 'bracket shift' Transition or the value has not yet been calculated.
Grammar.Production	p A Grammar.Production to apply when following this 'reduce' Transition, or 'null' if this is not a 'reduce' Transition.
NDFA.State	to The State to which this Transition leads.

Constructor Summary

NDFA.Transition(NDFA.State to)
Constructs a 'no-op' Transition, given values for its non-null fields.

NDFA.Transition(NDFA.State to, Grammar.NonTerminal g)
Constructs an 'open' Transition, given values for its non-null fields.

NDFA.Transition(NDFA.State to, Grammar.Production p)
Constructs a 'reduce' Transition, given values for its non-null fields.

NDFA.Transition(NDFA.State to, Grammar.Terminal g)
Constructs a 'shift' Transition (bracket or otherwise), given values for its non-null fields.

Method Summary

java.lang.String

toString() Returns a brief decription of this Transition.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

to

public final NDFA.State to

The State to which this Transition leads. This field is never null.

g

public final Grammar g

A Grammar describing the Tree that is constructed by following this Transition, or 'null'. Specifically:

• If this is a 'shift' Transition, this field holds a Grammar.Terminal (perhaps a Grammar.Bracket).
• If this is an 'open' Transition, this field holds a Grammar.NonTerminal.
• If this is a 'no-op' or 'reduce' Transition, this field is null.

p

public final Grammar.Production p

A Grammar.Production to apply when following this 'reduce' Transition, or 'null' if this is not a 'reduce' Transition.

ndfa

public NDFA ndfa

An NDFA describing the grammar of the contents of the bracket, if this is a 'bracket shift' Transition and its NDFA has already been calculated, or 'null' if this is not a 'bracket shift' Transition or the value has not yet been calculated. Calculating the NDFA is the caller's responsibility, but it involves nothing more complicated than calling 'make()'.

Constructor Detail

NDFA.Transition

public NDFA.Transition(NDFA.State to)

Constructs a 'no-op' Transition, given values for its non-null fields.

NDFA.Transition

public NDFA.Transition(NDFA.State to,
                       Grammar.Terminal g)

Constructs a 'shift' Transition (bracket or otherwise), given values for its non-null fields.

NDFA.Transition

public NDFA.Transition(NDFA.State to,
                       Grammar.NonTerminal g)

Constructs an 'open' Transition, given values for its non-null fields.

NDFA.Transition

public NDFA.Transition(NDFA.State to,
                       Grammar.Production p)

Constructs a 'reduce' Transition, given values for its non-null fields.

Method Detail

toString

public java.lang.String toString()

Returns a brief decription of this Transition. Specifically, returns "No-op" or "Open", or "Shift[x]" where "x" is 'g.toString()', or "Reduce[x]" where "x" is 'p.name'.

Overrides:

toString in class java.lang.Object